/*******************************************************************************
*
* Module Name: utmath - Integer math support routines
*
******************************************************************************/
/******************************************************************************
*
* 1. Copyright Notice
*
* Some or all of this work - Copyright (c) 1999 - 2011, Intel Corp.
* All rights reserved.
*
* 2. License
*
* 2.1. This is your license from Intel Corp. under its intellectual property
* rights. You may have additional license terms from the party that provided
* you this software, covering your right to use that party's intellectual
* property rights.
*
* 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
* copy of the source code appearing in this file ("Covered Code") an
* irrevocable, perpetual, worldwide license under Intel's copyrights in the
* base code distributed originally by Intel ("Original Intel Code") to copy,
* make derivatives, distribute, use and display any portion of the Covered
* Code in any form, with the right to sublicense such rights; and
*
* 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
* license (with the right to sublicense), under only those claims of Intel
* patents that are infringed by the Original Intel Code, to make, use, sell,
* offer to sell, and import the Covered Code and derivative works thereof
* solely to the minimum extent necessary to exercise the above copyright
* license, and in no event shall the patent license extend to any additions
* to or modifications of the Original Intel Code. No other license or right
* is granted directly or by implication, estoppel or otherwise;
*
* The above copyright and patent license is granted only if the following
* conditions are met:
*
* 3. Conditions
*
* 3.1. Redistribution of Source with Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification with rights to further distribute source must include
* the above Copyright Notice, the above License, this list of Conditions,
* and the following Disclaimer and Export Compliance provision. In addition,
* Licensee must cause all Covered Code to which Licensee contributes to
* contain a file documenting the changes Licensee made to create that Covered
* Code and the date of any change. Licensee must include in that file the
* documentation of any changes made by any predecessor Licensee. Licensee
* must include a prominent statement that the modification is derived,
* directly or indirectly, from Original Intel Code.
*
* 3.2. Redistribution of Source with no Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification without rights to further distribute source must
* include the following Disclaimer and Export Compliance provision in the
* documentation and/or other materials provided with distribution. In
* addition, Licensee may not authorize further sublicense of source of any
* portion of the Covered Code, and must include terms to the effect that the
* license from Licensee to its licensee is limited to the intellectual
* property embodied in the software Licensee provides to its licensee, and
* not to intellectual property embodied in modifications its licensee may
* make.
*
* 3.3. Redistribution of Executable. Redistribution in executable form of any
* substantial portion of the Covered Code or modification must reproduce the
* above Copyright Notice, and the following Disclaimer and Export Compliance
* provision in the documentation and/or other materials provided with the
* distribution.
*
* 3.4. Intel retains all right, title, and interest in and to the Original
* Intel Code.
*
* 3.5. Neither the name Intel nor any other trademark owned or controlled by
* Intel shall be used in advertising or otherwise to promote the sale, use or
* other dealings in products derived from or relating to the Covered Code
* without prior written authorization from Intel.
*
* 4. Disclaimer and Export Compliance
*
* 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
* HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
* IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
* INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
* UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
* IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
* PARTICULAR PURPOSE.
*
* 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
* OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
* COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
* SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
* CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
* HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
* SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
* LIMITED REMEDY.
*
* 4.3. Licensee shall not export, either directly or indirectly, any of this
* software or system incorporating such software without first obtaining any
* required license or other approval from the U. S. Department of Commerce or
* any other agency or department of the United States Government. In the
* event Licensee exports any such software from the United States or
* re-exports any such software from a foreign destination, Licensee shall
* ensure that the distribution and export/re-export of the software is in
* compliance with all laws, regulations, orders, or other restrictions of the
* U.S. Export Administration Regulations. Licensee agrees that neither it nor
* any of its subsidiaries will export/re-export any technical data, process,
* software, or service, directly or indirectly, to any country for which the
* United States government or any agency thereof requires an export license,
* other governmental approval, or letter of assurance, without first obtaining
* such license, approval or letter.
*
*****************************************************************************/
#define __UTMATH_C__
#include "acpi.h"
#include "accommon.h"
#define _COMPONENT ACPI_UTILITIES
ACPI_MODULE_NAME ("utmath")
/*
* Optional support for 64-bit double-precision integer divide. This code
* is configurable and is implemented in order to support 32-bit kernel
* environments where a 64-bit double-precision math library is not available.
*
* Support for a more normal 64-bit divide/modulo (with check for a divide-
* by-zero) appears after this optional section of code.
*/
#ifndef ACPI_USE_NATIVE_DIVIDE
/* Structures used only for 64-bit divide */
typedef struct uint64_struct
{
UINT32 Lo;
UINT32 Hi;
} UINT64_STRUCT;
typedef union uint64_overlay
{
UINT64 Full;
UINT64_STRUCT Part;
} UINT64_OVERLAY;
/*******************************************************************************
*
* FUNCTION: AcpiUtShortDivide
*
* PARAMETERS: Dividend - 64-bit dividend
* Divisor - 32-bit divisor
* OutQuotient - Pointer to where the quotient is returned
* OutRemainder - Pointer to where the remainder is returned
*
* RETURN: Status (Checks for divide-by-zero)
*
* DESCRIPTION: Perform a short (maximum 64 bits divided by 32 bits)
* divide and modulo. The result is a 64-bit quotient and a
* 32-bit remainder.
*
******************************************************************************/
ACPI_STATUS
AcpiUtShortDivide (
UINT64 Dividend,
UINT32 Divisor,
UINT64 *OutQuotient,
UINT32 *OutRemainder)
{
UINT64_OVERLAY DividendOvl;
UINT64_OVERLAY Quotient;
UINT32 Remainder32;
ACPI_FUNCTION_TRACE (UtShortDivide);
/* Always check for a zero divisor */
if (Divisor == 0)
{
ACPI_ERROR ((AE_INFO, "Divide by zero"));
return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
}
DividendOvl.Full = Dividend;
/*
* The quotient is 64 bits, the remainder is always 32 bits,
* and is generated by the second divide.
*/
ACPI_DIV_64_BY_32 (0, DividendOvl.Part.Hi, Divisor,
Quotient.Part.Hi, Remainder32);
ACPI_DIV_64_BY_32 (Remainder32, DividendOvl.Part.Lo, Divisor,
Quotient.Part.Lo, Remainder32);
/* Return only what was requested */
if (OutQuotient)
{
*OutQuotient = Quotient.Full;
}
if (OutRemainder)
{
*OutRemainder = Remainder32;
}
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: AcpiUtDivide
*
* PARAMETERS: InDividend - Dividend
* InDivisor - Divisor
* OutQuotient - Pointer to where the quotient is returned
* OutRemainder - Pointer to where the remainder is returned
*
* RETURN: Status (Checks for divide-by-zero)
*
* DESCRIPTION: Perform a divide and modulo.
*
******************************************************************************/
ACPI_STATUS
AcpiUtDivide (
UINT64 InDividend,
UINT64 InDivisor,
UINT64 *OutQuotient,
UINT64 *OutRemainder)
{
UINT64_OVERLAY Dividend;
UINT64_OVERLAY Divisor;
UINT64_OVERLAY Quotient;
UINT64_OVERLAY Remainder;
UINT64_OVERLAY NormalizedDividend;
UINT64_OVERLAY NormalizedDivisor;
UINT32 Partial1;
UINT64_OVERLAY Partial2;
UINT64_OVERLAY Partial3;
ACPI_FUNCTION_TRACE (UtDivide);
/* Always check for a zero divisor */
if (InDivisor == 0)
{
ACPI_ERROR ((AE_INFO, "Divide by zero"));
return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
}
Divisor.Full = InDivisor;
Dividend.Full = InDividend;
if (Divisor.Part.Hi == 0)
{
/*
* 1) Simplest case is where the divisor is 32 bits, we can
* just do two divides
*/
Remainder.Part.Hi = 0;
/*
* The quotient is 64 bits, the remainder is always 32 bits,
* and is generated by the second divide.
*/
ACPI_DIV_64_BY_32 (0, Dividend.Part.Hi, Divisor.Part.Lo,
Quotient.Part.Hi, Partial1);
ACPI_DIV_64_BY_32 (Partial1, Dividend.Part.Lo, Divisor.Part.Lo,
Quotient.Part.Lo, Remainder.Part.Lo);
}
else
{
/*
* 2) The general case where the divisor is a full 64 bits
* is more difficult
*/
Quotient.Part.Hi = 0;
NormalizedDividend = Dividend;
NormalizedDivisor = Divisor;
/* Normalize the operands (shift until the divisor is < 32 bits) */
do
{
ACPI_SHIFT_RIGHT_64 (NormalizedDivisor.Part.Hi,
NormalizedDivisor.Part.Lo);
ACPI_SHIFT_RIGHT_64 (NormalizedDividend.Part.Hi,
NormalizedDividend.Part.Lo);
} while (NormalizedDivisor.Part.Hi != 0);
/* Partial divide */
ACPI_DIV_64_BY_32 (NormalizedDividend.Part.Hi,
NormalizedDividend.Part.Lo,
NormalizedDivisor.Part.Lo,
Quotient.Part.Lo, Partial1);
/*
* The quotient is always 32 bits, and simply requires adjustment.
* The 64-bit remainder must be generated.
*/
Partial1 = Quotient.Part.Lo * Divisor.Part.Hi;
Partial2.Full = (UINT64) Quotient.Part.Lo * Divisor.Part.Lo;
Partial3.Full = (UINT64) Partial2.Part.Hi + Partial1;
Remainder.Part.Hi = Partial3.Part.Lo;
Remainder.Part.Lo = Partial2.Part.Lo;
if (Partial3.Part.Hi == 0)
{
if (Partial3.Part.Lo >= Dividend.Part.Hi)
{
if (Partial3.Part.Lo == Dividend.Part.Hi)
{
if (Partial2.Part.Lo > Dividend.Part.Lo)
{
Quotient.Part.Lo--;
Remainder.Full -= Divisor.Full;
}
}
else
{
Quotient.Part.Lo--;
Remainder.Full -= Divisor.Full;
}
}
Remainder.Full = Remainder.Full - Dividend.Full;
Remainder.Part.Hi = (UINT32) -((INT32) Remainder.Part.Hi);
Remainder.Part.Lo = (UINT32) -((INT32) Remainder.Part.Lo);
if (Remainder.Part.Lo)
{
Remainder.Part.Hi--;
}
}
}
/* Return only what was requested */
if (OutQuotient)
{
*OutQuotient = Quotient.Full;
}
if (OutRemainder)
{
*OutRemainder = Remainder.Full;
}
return_ACPI_STATUS (AE_OK);
}
#else
/*******************************************************************************
*
* FUNCTION: AcpiUtShortDivide, AcpiUtDivide
*
* PARAMETERS: See function headers above
*
* DESCRIPTION: Native versions of the UtDivide functions. Use these if either
* 1) The target is a 64-bit platform and therefore 64-bit
* integer math is supported directly by the machine.
* 2) The target is a 32-bit or 16-bit platform, and the
* double-precision integer math library is available to
* perform the divide.
*
******************************************************************************/
ACPI_STATUS
AcpiUtShortDivide (
UINT64 InDividend,
UINT32 Divisor,
UINT64 *OutQuotient,
UINT32 *OutRemainder)
{
ACPI_FUNCTION_TRACE (UtShortDivide);
/* Always check for a zero divisor */
if (Divisor == 0)
{
ACPI_ERROR ((AE_INFO, "Divide by zero"));
return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
}
/* Return only what was requested */
if (OutQuotient)
{
*OutQuotient = InDividend / Divisor;
}
if (OutRemainder)
{
*OutRemainder = (UINT32) (InDividend % Divisor);
}
return_ACPI_STATUS (AE_OK);
}
ACPI_STATUS
AcpiUtDivide (
UINT64 InDividend,
UINT64 InDivisor,
UINT64 *OutQuotient,
UINT64 *OutRemainder)
{
ACPI_FUNCTION_TRACE (UtDivide);
/* Always check for a zero divisor */
if (InDivisor == 0)
{
ACPI_ERROR ((AE_INFO, "Divide by zero"));
return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
}
/* Return only what was requested */
if (OutQuotient)
{
*OutQuotient = InDividend / InDivisor;
}
if (OutRemainder)
{
*OutRemainder = InDividend % InDivisor;
}
return_ACPI_STATUS (AE_OK);
}
#endif